Sajid Javid, the Communities Secretary, has threatened to cancel a major Palestinian cultural festival in central London next month over support for terror group Hamas.

Palestinian Expo is scheduled to take place on the weekend of July 8-9 at the QE2 centre but it is now in doubt following a letter from Mr Javid to the organising group Friends of Al-Aqsa (FOA).

The FOA has advertised the event – billed as featuring political conversation, comedy acts, workshops and food - as "the biggest in Europe".

In a letter sent on June 14, Mr Javid said he was considering calling it off, citing: "concerns that your organisation and those connected with it have expressed public support for a proscribed organisation, namely Hamas, and that you have supported events at which Hamas and Hizballah – also proscribed – have been praised”.

Ismail Patel, founder of Friends of Al-Aqsa, is closely linked to several Islamic organisations and has openly expressed support for Hamas in the past, calling the group "no terrorist organisation."

The Leicester-based FOA organisation has actively promoted boycotts of Israel and has hosted antisemitic musician Gilad Atzmon and Holocaust denier Paul Eisen on its website.

In a letter replying to the Secretary of State, Mr Patel said the government was unlawfully interfering in the event.

Mr Patel said ministers had " failed to provide any satisfactory reason as to why they have chosen to cancel an event which seeks to celebrate Palestinian culture and heritage."

Mr Javid had initially said he would deliver a final verdict on whether the Expo could take place last Friday- but the decision is said to have been delayed because of the Grenfell Tower fire.

The FOA has now begun a crowd-funding campaign to raise money for a possible legal challenge if the festival is cancelled.

Mr Patel  also accused the government of acting on hearsay from a pro-Israeli lobby group.

He told the Guardian: “Despite the threat from DCLG, we will make further efforts to hold Palestine Expo and will seek a judicial review of this unfair and unjust decision.”

Speakers booked for Palestinian Expo include journalist John Pilger, anti-Zionist academic Illan Pappe and BDS activist Ben White.

Organisers claim to have sold around 2,000 £20 tickets and expect a total of 10,000 people to attend.